The Sunlight Experiment

Supplement Monograph

MK-677 (Ibutamoren)

GhOral

MK-677 (ibutamoren) is an orally active, non-peptide ghrelin-receptor agonist that raises growth hormone and IGF-1; it is an investigational drug, not an approved supplement.

Work in progress Updated July 2026

What Is MK-677?

MK-677 (ibutamoren, also written MK-0677) is an orally active, non-peptide ghrelin-receptor (GHSR) agonist — a growth hormone secretagogue that makes the body release more of its own growth hormone and IGF-1. Unlike the injectable GH-releasing peptides, it is taken by mouth and produces sustained increases in the GH/IGF-1 axis. It has been studied in real, published randomised controlled trials, but it is an investigational drug that was never approved by the FDA for any indication, and it is not a dietary supplement.

Evidence

MK-677 has genuine clinical-trial data, mostly around its ability to raise IGF-1. In a randomised, double-blind, placebo-controlled trial in healthy elderly subjects, oral MK-677 increased the GH–IGF-1 axis 1Reference 1Chapman IM et al. · 1996RCTStimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral MK-677 in healthy elderly subjects — randomised trialView study →, and across several randomised studies in older adults it raised serum IGF-1 by roughly 55–94% and increased markers of bone turnover 2Reference 2Murphy MG et al. · 1999RCTOral MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults — randomised trialsView study →. A large 12-month randomised trial of 563 patients with mild-to-moderate Alzheimer’s disease confirmed target engagement (serum IGF-1 rose ~73%) but found MK-677 was ineffective at slowing Alzheimer’s progression 3Reference 3Sevigny JJ et al. · 2008RCTGrowth hormone secretagogue MK-677: no clinical effect on Alzheimer’s disease progression — randomised trialView study →. So while the drug reliably moves the GH/IGF-1 axis, evidence that this translates into meaningful benefits for muscle, ageing, or cognition is weak or negative. Popular claims about lean-mass gains and “anti-ageing” are not supported by a positive clinical outcome trial in this pass.

Dosage & Safety

The most common dose in clinical trials was 25 mg orally once daily 1,3Reference 1Chapman IM et al. · 1996RCTStimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral MK-677 in healthy elderly subjects — randomised trialView study →Reference 3Sevigny JJ et al. · 2008RCTGrowth hormone secretagogue MK-677: no clinical effect on Alzheimer’s disease progression — randomised trialView study →. MK-677 is an investigational drug, not an approved dietary supplement or medicine, and this page is informational only — not a recommendation. Known concerns from the trials include increased IGF-1, reduced insulin sensitivity / raised blood glucose, fluid retention, and increased appetite; long-term safety is not established. It is prohibited in sport (WADA). Drug interactions and pregnancy/lactation safety are not assessed in this pass. Not for self-administration.

References

  1. Chapman IM, et al. (1996). Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral MK-677 in healthy elderly subjects — randomised trial. J Clin Endocrinol Metab. https://pubmed.ncbi.nlm.nih.gov/8954023/
  2. Murphy MG, et al. (1999). Oral MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults — randomised trials. J Bone Miner Res. https://pubmed.ncbi.nlm.nih.gov/10404019/
  3. Sevigny JJ, et al. (2008). Growth hormone secretagogue MK-677: no clinical effect on Alzheimer’s disease progression — randomised trial. Neurology. https://pubmed.ncbi.nlm.nih.gov/19015485/